Detailed Process Flow Of PCB Production (2)

Sixth, the outer layer; the outer layer is roughly the same as the inner layer process of the first step, and its purpose is to facilitate the subsequent process to make a circuit

1. Pre-treatment: Clean the surface of the board by pickling, grinding and drying to increase the adhesion of the dry film.

2. Lamination: Paste the dry film on the surface of the PCB substrate to prepare for the subsequent image transfer.

3. Exposure: UV light irradiation is performed to make the dry film on the board form a state of polymerization and non-polymerization.

4. Development: Dissolve the dry film that is not polymerized during the exposure process, leaving a gap.

Seventh,Secondary copper and etching; secondary copper plating, etching

1. Two copper: The electroplating pattern, the chemical copper is applied to the place where the dry film is not covered in the hole; at the same time, the conductivity and copper thickness are further increased, and then tinned to protect the integrity of the lines and holes during etching.

2. SES: The bottom copper of the outer layer dry film (wet film) attachment area is etched through processes such as film removal, etching, and tin stripping, and the outer layer circuit is now completed.

Eight, solder mask: can protect the board, prevent oxidation and other phenomena

1. Pre-treatment: pickling, ultrasonic washing and other processes to remove board oxides and increase the roughness of the copper surface.

2. Printing: Cover the places where the PCB board does not need to be soldered with solder resist ink to protect and insulate.

3. Pre-bake: Dry the solvent in the solder mask ink while hardening the ink for exposure.

4. Exposure: Solder resist ink is cured by UV light irradiation, and high molecular polymer is formed by photopolymerization.

5. Development: remove the sodium carbonate solution in the unpolymerized ink.

6. Post-bake: to completely harden the ink.

Nine,Text; printed text

1. Pickling: Clean the surface of the board, remove surface oxidation to strengthen the adhesion of printing ink.

2. Text: printed text is convenient for subsequent welding process.

Ten, Surface treatment OSP; the side of the bare copper plate to be welded is coated to form an organic film to prevent rust and oxidation

Eleven, Forming; gong out the shape of the board required by customers, which is convenient for customers to carry out SMT patch and assembly

Twelve, Flying probe test; test the circuit of the board to avoid the outflow of the short-circuit board

Thirteen, FQC; final inspection, complete sampling and full inspection after all processes are completed

Fourteen, packaging, out of the warehouse; vacuum packaging the finished PCB board, packaging and shipping, and completing the delivery